Learning iPhone programming

[janine]

So here's the plan:

We'll begin at the February 23rd meeting. At the end of the regular
meeting each month, I'll run through the Keynote presentation given by
Mark Dalrymple to the Pittsburgh chapter, giving an overview of the
material to be covered in the coming month. Then we'll have a Q&A
session. After that, everyone will work their way through that
month's chapters on their own, with help from the mentors as needed.

Instead of having official office hours during the month, we're asking
people to post their questions here. The mentors will monitor the
group and answer questions as they come up. They may choose to work
one-on-one with someone if it's needed, but the more we can keep the
answers in a public forum the more everyone will benefit from them.

Between now and February 23rd, everyone who wants to participate has
some homework to do:

1. Make sure you have a copy of the book, Beginning iPhone 4
Development, by Dave Mark, Jeff LaMarche and Jack Nutting (published
by Apress). You can get a copy of the ebook for 25% off by going to
apress.com and using the discount code "APRESSCOCOAHEADS2011". (this
is also good on all their other Mac and iPhone books, through
3/31/11).

2. Sign up with Apple's iOS Developer Program, which costs $99
(http://developer.apple.com/programs/start/standard/). You need this
in order to be able to run your own programs on an iOS device.

3. Brush up on your Objective-C, if you're not already familiar with
it. There are lots of books out there, and Apple also provides free
documentation:
http://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/ObjectiveC/Introduction/introObjectiveC.html

Thanks for participating! I'll post news here as stuff comes up.

janine

[Matt Blair]

I just noticed that the new edition of the book is now available to
subscribers of Safari Bookshelf from O'Reilly:

http://my.safaribooksonline.com/book/programming/iphone/9781430230243

Matt

> documentation:http://developer.apple.com/library/mac/#documentation/Cocoa/Conceptua...

[Janine Ohmer]

Great catch, thanks!

janine

[to'c]

janine:

How many sessions (months) do you plan on taking to get thru the book? About how many hours/month of work might be involved?

to'c

[Janine Ohmer]

Hi,

MarkD, the author of the program, plans to do about one chapter per week. I have no idea how many hours that will take. If we start losing people it's possible for us to slow it down; that will be decided as we go along.

janine

[Frank Escamilla]

Janine, thanks for organizing this! I'm psyched to get started on it. Quick question: will a free developer account be sufficient to do the work in the text with the simulators, or is it going to be necessary to do hardware development?

Thanks!
Frank

[Janine Ohmer]

You can do most of the work in the simulator; however some things, such as the camera and accelerometer, will not be available to you. Also the process of getting your app to run on a device can be fraught with danger and heffalump traps (http://en.wikipedia.org/wiki/Heffalump_trap), so being able to go through that process with help on hand will pay off in the long run.

Personally, the thrill of seeing my own app running on my phone for the first time was well worth the $99.

janine

[Justin R. Miller]

Couple other points about simulator use:

* Things like GameKit (Bluetooth P2P gaming stuff) are impossible.
* It's always useful to see performance on-device.

For the latter, when you start small, it doesn't matter too much, but once you get into development, it's essential to see how things work on a memory- and CPU-limited device.

That said, I forget what the turnaround time is for paying the $99, but you could always start off with simulator and then pull the trigger later, with a small wait.

JM

--
Justin R. Miller
Code Sorcery Workshop, LLC
http://codesorcery.net

[Frank Escamilla]

Yep definitely good points. I think I'm sold on the full development account then, sounds like it will be well worth the 99 bucks.

Thanks,
Frank

[Steven W Riggins]

And the simulator is just broken for some things. I had code just yesterday that worked fine in the sim, but not on an iPhone 4. /Shrug

[Matt Blair]

More simulator quirks:

MapKit in the Simulator can be really sluggish at random intervals. It
will be fine, then seconds later it's almost unresponsive, then fine
again.

Core Location always returns the coordinates for 1 Inifinite Loop in
Cupertino. Last time I checked, there was no way to change this, so
this limits your location testing in the simulator quite a bit.

I've noticed inconsistent storage of User Defaults in the Simulator,
which can cause erratic app behavior if you are using the defaults in
any serious way. I've never spent a whole lot of time isolating why
this happens in the simulator, because...

Never waste time investigating strange behavior, errors or warnings in
the console that only appear when using the Simulator. Write for the
devices, not the simulator, and only spend time troubleshooting a
problem if it happens on a device. I learned that lesson early on, but
not early enough.

Matt

[Justin R. Miller]

Good points on the sim. One thing worth noting about preferences, however is that they are in ~/Library/Application Support/iPhone Simulator and are broken down by OS version. Very handy for debugging plists or putting things into app document folders.

JM

[Michael]

I've looked at the TOC for the book and it looks like the camera section
doesn't kick in until chapter 18.
I have an iPod Touch w/o camera. I'm assuming that I can do most of the
projects on that?

One question I have is how likely am I to destroy my iPod with my rogue
under-dev app? Should I be
thinking a second iPod as a dev platform only?

MW

[Justin R. Miller]

I've not heard of anything you can do to a device at the app level that could irrevocably harm it. You can always delete the app.

If, however, you are trying a dev version of the OS, Apple makes that very difficult to go back a version.

Otherwise, you should not need a second device for most dev. I dev on my real, production, only cell phone and my only iPad.

JM

[Tim O'Connor]

I also develop on my personal iPod. My second one, actually, and have seen no problems. Of course, it's a *very* simple app...

Another thrill, well worth the $99, is showing your app to someone who then grabs your iPod and gushes for the next 20 minutes, running around and showing it to everyone that will look. Sure there was beer involved but it sure gave me a warm glow!